From lab to real world: making scrap glass a valuable commodity

Published: 16 December 2021
Glass fines used at Geddes Crescent Reserve

Research funded by Sustainability Victoria (SV) will transform a previously unusable portion of household glass waste into a valuable resource in the construction industry.

Assisted with grants by our Research and Development Fund, Swinburne University of Technology and the University of Melbourne led collaborative projects that researched, tested and industry-approved the use of recycled glass fines in common construction products.

Finding a use for tiny pieces of broken glass

As your local glass recycling truck does the rounds in your neighbourhood, glass inevitably breaks during collection. While larger pieces of broken glass can be sorted into colours and types to be remade into new glass products, tiny pieces of contaminated broken glass, called fines, have previously had no end-use and have been stockpiled or sent to landfill.

In addition to creating a use for this waste stream, approval from the Department of Transport (formerly VicRoads) will likely see a reduction in the costs of these construction products as they will require less processing and may be preferred over more expensive raw materials. Recycled glass can be turned into new products in the regional area they are collected from, instead of needing to be transported to metro areas for processing.

Swinburne University of Technology led a collaborative research project with Alex Fraser Group and the Department of Transport to investigate the use of these glass fines in cement treated pavement –widely used in road construction in Victoria.

Building upon existing research in the field, the university successfully trialled a new road base mix for lower trafficked roads that contains a much higher percentage of glass fines. With the Department of Transport updating its specification for the use of recycled glass in roads, local and state government can use much more of our recycled glass in Victoria’s expanding road and footpath network.

Finding a use for unwashed recycled glass

The University of Melbourne has also found a new use for these previously unusable glass fines.

Typically, recycled glass fines in concrete are required to be thoroughly washed first as contamination in the glass on concrete properties was unknown due to lack of available research and testing.

Leading a project with collaborative partners the Level Crossing Removal Project’s North West Program Alliance, the Department of Transport (DoT), Hanson Australia and KBR, the university successfully proved that unwashed recycled glass fines can be used in concrete paving with insignificant effects on performance.

The university’s product testing assessed the strength, durability and comparable measures to current concrete standards. The product was used in the new Reservoir Station build and helped the project receive a 5 Star Green Star rating.

The Department of Transport has approved this new use of unwashed recycled glass and has updated the relevant specification (Section 703 – General Concrete Paving).

This increase in demand will support the regional recycling industry into robust businesses and will reduce carbon outputs associated with transportation of glass processing.

Thanks to the investment of the Victorian Government, this major breakthrough will take experimental research into the mainstream.

Future demand for recycled glass

These two projects show there is scope for a broad application of recycled glass fines across local and state government infrastructure and road projects. The more we can use products already in circulation the less we need to dig up, process and transport virgin materials from the ground.

By creating markets across regional and metro Victoria, the glass recycling industry can grow. An increase in demand for these products will see an economy of scale benefit.

Thanks to these projects, most of the contents of your local glass recycling truck can be reused, and there’s a better chance it may even be in the road your truck is travelling on.

Learn more about how SV’s Research and Development grants are contributing to Victoria’s transition to a circular economy.